Numerous tasks require people to work with their arms outstretched, e.g., while operating hand tools or other equipment that they must at least partially support themselves. Examples include construction, surgery, dentistry, painting, dishwashing, and product assembly. Persons engaged in such activities may experience fatigue from prolonged muscular efforts required to resist the force of gravity on their arms in order to keep them extended. Weak or disabled persons may experience fatigue performing daily tasks. Static arm rests on chairs and work tables are only effective if the task is performed within a relatively restricted area, for example, at a computer keyboard. Tasks that involve a greater range of motion are not aided by static armrests.
Thus, there is a need for systems that may relieve fatigue experienced by persons performing tasks involving moderate to large ranges of motion and/or operating tools or other equipment.